refactor(edge): 抽取边缘运行时共享包并完成 Phase 3 重构

- 新增 internal/apps/edge/，三组件改为薄包装，删除 3000+ 行重复代码
- Agent 心跳周期下沉至 heartbeat/cycle.go
- 协议类型迁入 pkg/protocol/agent.go
- 补充设计文档与 changelog

internal/apps/edge/config/duration.go

@@ -0,0 +1,54 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type MillisecondDuration time.Duration
+
+func (d MillisecondDuration) Duration() time.Duration {
+	return time.Duration(d)
+}
+
+func (d MillisecondDuration) String() string {
+	return time.Duration(d).String()
+}
+
+func (d *MillisecondDuration) UnmarshalJSON(data []byte) error {
+	raw := strings.TrimSpace(string(data))
+	if raw == "" || raw == "null" {
+		*d = 0
+		return nil
+	}
+	if strings.HasPrefix(raw, "\"") {
+		var text string
+		if err := json.Unmarshal(data, &text); err != nil {
+			return err
+		}
+		text = strings.TrimSpace(text)
+		if text == "" {
+			*d = 0
+			return nil
+		}
+		parsed, err := time.ParseDuration(text)
+		if err != nil {
+			return fmt.Errorf("invalid duration string %q: %w", text, err)
+		}
+		*d = MillisecondDuration(parsed)
+		return nil
+	}
+	ms, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil {
+		return fmt.Errorf("invalid duration milliseconds %q: %w", raw, err)
+	}
+	*d = MillisecondDuration(time.Duration(ms) * time.Millisecond)
+	return nil
+}
+
+func (d MillisecondDuration) MarshalJSON() ([]byte, error) {
+	return json.Marshal(time.Duration(d).Milliseconds())
+}

internal/apps/edge/config/duration_test.go

@@ -0,0 +1,53 @@
+package config
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+)
+
+func TestMillisecondDurationUnmarshalJSON(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    time.Duration
+		wantErr bool
+	}{
+		{name: "null", input: "null", want: 0},
+		{name: "empty", input: `""`, want: 0},
+		{name: "integer milliseconds", input: "30000", want: 30 * time.Second},
+		{name: "duration string", input: `"5s"`, want: 5 * time.Second},
+		{name: "invalid number", input: "not-a-number", wantErr: true},
+		{name: "invalid duration string", input: `"not-a-duration"`, wantErr: true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var d MillisecondDuration
+			err := json.Unmarshal([]byte(tt.input), &d)
+			if tt.wantErr {
+				if err == nil {
+					t.Fatal("expected error")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if d.Duration() != tt.want {
+				t.Fatalf("got %s, want %s", d, tt.want)
+			}
+		})
+	}
+}
+
+func TestMillisecondDurationMarshalJSON(t *testing.T) {
+	d := MillisecondDuration(7 * time.Second)
+	data, err := json.Marshal(d)
+	if err != nil {
+		t.Fatalf("Marshal failed: %v", err)
+	}
+	if string(data) != "7000" {
+		t.Fatalf("unexpected marshaled value: %s", string(data))
+	}
+}

internal/apps/edge/heartbeat/autoupdate.go

@@ -0,0 +1,41 @@
+package heartbeat
+
+import (
+	"context"
+	"log/slog"
+	"strings"
+
+	edgeupdater "github.com/Rain-kl/Wavelet/internal/apps/edge/updater"
+)
+
+type AutoUpdateSettings struct {
+	AutoUpdate    bool
+	UpdateNow     bool
+	UpdateRepo    string
+	UpdateChannel string
+	UpdateTag     string
+}
+
+func TryAutoUpdate(ctx context.Context, updater *edgeupdater.Service, settings *AutoUpdateSettings, logLabel string) {
+	if settings == nil || updater == nil {
+		return
+	}
+	force := settings.UpdateNow
+	shouldCheck := settings.AutoUpdate || force
+	if !shouldCheck || strings.TrimSpace(settings.UpdateRepo) == "" {
+		return
+	}
+	channel := "stable"
+	if force && strings.TrimSpace(settings.UpdateChannel) != "" {
+		channel = settings.UpdateChannel
+	}
+	slog.Info("checking for "+logLabel+" updates", "repo", settings.UpdateRepo, "channel", channel, "force", force)
+	err := updater.CheckAndUpdate(ctx, settings.UpdateRepo, edgeupdater.UpdateOptions{
+		Channel: channel,
+		TagName: settings.UpdateTag,
+		Force:   force,
+	})
+	if err != nil {
+		slog.Error(logLabel+" update check failed", "error", err)
+	}
+}

internal/apps/edge/heartbeat/loop.go

@@ -0,0 +1,23 @@
+package heartbeat
+
+import (
+	"context"
+	"time"
+)
+
+// RunLoop invokes fn immediately, then on each interval tick until ctx is cancelled.
+func RunLoop(ctx context.Context, interval time.Duration, fn func(context.Context)) {
+	fn(ctx)
+
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			fn(ctx)
+		}
+	}
+}

internal/apps/edge/heartbeat/loop_test.go

@@ -0,0 +1,41 @@
+package heartbeat
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestRunLoopImmediateAndTicker(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	var calls atomic.Int32
+	interval := 20 * time.Millisecond
+
+	done := make(chan struct{})
+	go func() {
+		RunLoop(ctx, interval, func(context.Context) {
+			calls.Add(1)
+		})
+		close(done)
+	}()
+
+	time.Sleep(5 * time.Millisecond)
+	if got := calls.Load(); got != 1 {
+		t.Fatalf("expected 1 immediate call, got %d", got)
+	}
+
+	time.Sleep(35 * time.Millisecond)
+	if got := calls.Load(); got < 2 {
+		t.Fatalf("expected at least 2 calls after ticker, got %d", got)
+	}
+
+	cancel()
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("RunLoop did not exit after context cancellation")
+	}
+}

internal/apps/edge/httpclient/client.go

@@ -0,0 +1,132 @@
+package httpclient
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type Client struct {
+	baseURL    string
+	token      string
+	authHeader string
+	httpClient *http.Client
+}
+
+func New(baseURL, token string, timeout time.Duration, authHeader string) *Client {
+	return &Client{
+		baseURL:    strings.TrimRight(baseURL, "/"),
+		token:      token,
+		authHeader: authHeader,
+		httpClient: &http.Client{Timeout: timeout},
+	}
+}
+
+func (c *Client) SetToken(token string) {
+	c.token = strings.TrimSpace(token)
+	slog.Debug("http client token updated")
+}
+
+func (c *Client) GetJSON(ctx context.Context, path string, target any) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.baseURL+path, nil)
+	if err != nil {
+		return err
+	}
+	c.setAuthHeader(req)
+	return c.do(req, target)
+}
+
+func (c *Client) PostJSON(ctx context.Context, path string, body any, target any) error {
+	data, err := json.Marshal(body)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+path, bytes.NewReader(data))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	c.setAuthHeader(req)
+	return c.do(req, target)
+}
+
+func (c *Client) DoRaw(ctx context.Context, method, path string, headers map[string]string) (*http.Response, error) {
+	req, err := http.NewRequestWithContext(ctx, method, c.baseURL+path, nil)
+	if err != nil {
+		return nil, err
+	}
+	c.setAuthHeader(req)
+	for key, value := range headers {
+		req.Header.Set(key, value)
+	}
+	return c.httpClient.Do(req)
+}
+
+func (c *Client) setAuthHeader(req *http.Request) {
+	if c.authHeader != "" {
+		req.Header.Set(c.authHeader, c.token)
+	}
+}
+
+func (c *Client) do(req *http.Request, target any) error {
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		slog.Error("http request failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			slog.Error("failed to close response body", "error", err)
+		}
+	}(res.Body)
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		slog.Error("http response read failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	if res.StatusCode != http.StatusOK {
+		slog.Warn("http request returned non-200", "method", req.Method, "path", req.URL.Path, "status", res.Status)
+		return ReadBodyError(body, res.Status)
+	}
+	if target == nil {
+		return nil
+	}
+	if err = json.Unmarshal(body, target); err != nil {
+		slog.Error("http response decode failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	return nil
+}
+
+func APIError(msg string) error {
+	if strings.TrimSpace(msg) == "" {
+		return nil
+	}
+	return errors.New(msg)
+}
+
+func ReadBodyError(body []byte, fallback string) error {
+	var errBody struct {
+		ErrorMsg string `json:"error_msg"`
+	}
+	if err := json.Unmarshal(body, &errBody); err == nil && strings.TrimSpace(errBody.ErrorMsg) != "" {
+		return errors.New(errBody.ErrorMsg)
+	}
+	return errors.New(fallback)
+}
+
+func ReadHTTPError(res *http.Response) error {
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return errors.New(res.Status)
+	}
+	return ReadBodyError(body, res.Status)
+}

internal/apps/edge/logging/logging.go

@@ -0,0 +1,33 @@
+package logging
+
+import (
+	"log/slog"
+	"os"
+	"strings"
+)
+
+type Options struct {
+	AddSource bool
+}
+
+func Setup(opts Options) {
+	handlerOpts := &slog.HandlerOptions{
+		AddSource: opts.AddSource,
+		Level:     ParseLevel(os.Getenv("LOG_LEVEL")),
+	}
+	handler := slog.NewTextHandler(os.Stdout, handlerOpts)
+	slog.SetDefault(slog.New(handler))
+}
+
+func ParseLevel(value string) slog.Level {
+	switch strings.ToLower(strings.TrimSpace(value)) {
+	case "debug":
+		return slog.LevelDebug
+	case "warn", "warning":
+		return slog.LevelWarn
+	case "error":
+		return slog.LevelError
+	default:
+		return slog.LevelInfo
+	}
+}

internal/apps/edge/nodeip/nodeip.go

@@ -0,0 +1,69 @@
+package nodeip
+
+import (
+	"context"
+	"net"
+	"time"
+
+	"github.com/Rain-kl/Wavelet/pkg/geoip"
+	"github.com/Rain-kl/Wavelet/pkg/geoip/iputil"
+)
+
+var (
+	LookupOutboundIP = geoip.GetOutboundIP
+	LookupLocalIP    = DetectLocal
+)
+
+func Detect() string {
+	if ip := detectOutbound(); ip != "" {
+		return ip
+	}
+	return LookupLocalIP()
+}
+
+func detectOutbound() string {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	ip, err := LookupOutboundIP(ctx)
+	if err != nil || ip == nil {
+		return ""
+	}
+	return ip.String()
+}
+
+func DetectLocal() string {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return ""
+	}
+	bestIP := ""
+	bestPriority := -1
+	for _, iface := range interfaces {
+		if iface.Flags&net.FlagUp == 0 || iface.Flags&net.FlagLoopback != 0 {
+			continue
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+		for _, addr := range addrs {
+			ipNet, ok := addr.(*net.IPNet)
+			if !ok || ipNet.IP == nil || ipNet.IP.IsLoopback() {
+				continue
+			}
+			ipv4 := ipNet.IP.To4()
+			if ipv4 == nil {
+				continue
+			}
+			priority := iputil.Score(ipv4)
+			if priority > bestPriority {
+				bestIP = ipv4.String()
+				bestPriority = priority
+			}
+			if bestPriority == 2 {
+				return bestIP
+			}
+		}
+	}
+	return bestIP
+}

internal/apps/edge/observability/linux.go

@@ -0,0 +1,268 @@
+package observability
+
+import (
+	"bufio"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+// ReadLinuxOSRelease returns the OS name and version from /etc/os-release.
+func ReadLinuxOSRelease() (string, string) {
+	file, err := os.Open("/etc/os-release")
+	if err != nil {
+		return runtime.GOOS, ""
+	}
+	defer file.Close()
+
+	values := make(map[string]string)
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		key, value, ok := strings.Cut(line, "=")
+		if !ok {
+			continue
+		}
+		values[key] = strings.Trim(value, `"`)
+	}
+	if pretty := strings.TrimSpace(values["PRETTY_NAME"]); pretty != "" {
+		return pretty, strings.TrimSpace(values["VERSION_ID"])
+	}
+	name := strings.TrimSpace(values["NAME"])
+	if name == "" {
+		name = runtime.GOOS
+	}
+	return name, strings.TrimSpace(values["VERSION_ID"])
+}
+
+// ReadLinuxCPUModel returns the CPU model name from /proc/cpuinfo.
+func ReadLinuxCPUModel() string {
+	file, err := os.Open("/proc/cpuinfo")
+	if err != nil {
+		return ""
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(strings.ToLower(line), "model name") {
+			_, value, ok := strings.Cut(line, ":")
+			if ok {
+				return strings.TrimSpace(value)
+			}
+		}
+	}
+	return ""
+}
+
+// ReadMemInfo returns total and used memory bytes from /proc/meminfo.
+func ReadMemInfo() (int64, int64) {
+	file, err := os.Open("/proc/meminfo")
+	if err != nil {
+		return 0, 0
+	}
+	defer file.Close()
+
+	var memTotalKB int64
+	var memAvailableKB int64
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := scanner.Text()
+		switch {
+		case strings.HasPrefix(line, "MemTotal:"):
+			memTotalKB = parseMemInfoValue(line)
+		case strings.HasPrefix(line, "MemAvailable:"):
+			memAvailableKB = parseMemInfoValue(line)
+		}
+	}
+
+	total := memTotalKB * 1024
+	if total == 0 {
+		return 0, 0
+	}
+	used := total - (memAvailableKB * 1024)
+	if used < 0 {
+		used = 0
+	}
+	return total, used
+}
+
+func parseMemInfoValue(line string) int64 {
+	fields := strings.Fields(line)
+	if len(fields) < 2 {
+		return 0
+	}
+	value, err := strconv.ParseInt(fields[1], 10, 64)
+	if err != nil {
+		return 0
+	}
+	return value
+}
+
+// ReadLinuxUptimeSeconds returns system uptime in seconds from /proc/uptime.
+func ReadLinuxUptimeSeconds() int64 {
+	content, err := os.ReadFile("/proc/uptime")
+	if err != nil {
+		return 0
+	}
+	fields := strings.Fields(string(content))
+	if len(fields) == 0 {
+		return 0
+	}
+	value, err := strconv.ParseFloat(fields[0], 64)
+	if err != nil {
+		return 0
+	}
+	return int64(value)
+}
+
+// ReadLinuxCPUStat returns aggregate CPU jiffies and idle jiffies from /proc/stat.
+func ReadLinuxCPUStat() (uint64, uint64) {
+	content, err := os.ReadFile("/proc/stat")
+	if err != nil {
+		return 0, 0
+	}
+	lines := strings.Split(string(content), "\n")
+	for _, line := range lines {
+		if !strings.HasPrefix(line, "cpu ") {
+			continue
+		}
+		fields := strings.Fields(line)
+		if len(fields) < 5 {
+			return 0, 0
+		}
+		var total uint64
+		for i := 1; i < len(fields); i++ {
+			value, err := strconv.ParseUint(fields[i], 10, 64)
+			if err != nil {
+				return 0, 0
+			}
+			total += value
+		}
+		idle, err := strconv.ParseUint(fields[4], 10, 64)
+		if err != nil {
+			return 0, 0
+		}
+		return total, idle
+	}
+	return 0, 0
+}
+
+// ReadLinuxNetworkTotals returns aggregate RX and TX byte totals from /proc/net/dev.
+func ReadLinuxNetworkTotals() (int64, int64) {
+	file, err := os.Open("/proc/net/dev")
+	if err != nil {
+		return 0, 0
+	}
+	defer file.Close()
+
+	var rx int64
+	var tx int64
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if !strings.Contains(line, ":") {
+			continue
+		}
+		name, data, ok := strings.Cut(line, ":")
+		if !ok {
+			continue
+		}
+		if strings.TrimSpace(name) == "lo" {
+			continue
+		}
+		fields := strings.Fields(data)
+		if len(fields) < 16 {
+			continue
+		}
+		rxValue, err := strconv.ParseInt(fields[0], 10, 64)
+		if err == nil {
+			rx += rxValue
+		}
+		txValue, err := strconv.ParseInt(fields[8], 10, 64)
+		if err == nil {
+			tx += txValue
+		}
+	}
+	return rx, tx
+}
+
+// ReadLinuxDiskTotals returns aggregate disk read and write byte totals from /proc/diskstats.
+func ReadLinuxDiskTotals() (int64, int64) {
+	file, err := os.Open("/proc/diskstats")
+	if err != nil {
+		return 0, 0
+	}
+	defer file.Close()
+
+	var readBytes int64
+	var writeBytes int64
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 14 {
+			continue
+		}
+		device := fields[2]
+		if shouldSkipDiskDevice(device) {
+			continue
+		}
+		readSectors, err := strconv.ParseInt(fields[5], 10, 64)
+		if err == nil {
+			readBytes += readSectors * 512
+		}
+		writeSectors, err := strconv.ParseInt(fields[9], 10, 64)
+		if err == nil {
+			writeBytes += writeSectors * 512
+		}
+	}
+	return readBytes, writeBytes
+}
+
+func shouldSkipDiskDevice(device string) bool {
+	switch {
+	case device == "":
+		return true
+	case strings.HasPrefix(device, "loop"),
+		strings.HasPrefix(device, "ram"),
+		strings.HasPrefix(device, "dm-"):
+		return true
+	default:
+		return false
+	}
+}
+
+// StatFilesystem returns total and used bytes for the filesystem containing path.
+func StatFilesystem(path string) (int64, int64) {
+	if strings.TrimSpace(path) == "" {
+		path = string(os.PathSeparator)
+	}
+	absPath := filepath.Clean(path)
+	var stat syscall.Statfs_t
+	if err := syscall.Statfs(absPath, &stat); err != nil {
+		return 0, 0
+	}
+	total := int64(stat.Blocks) * int64(stat.Bsize)
+	free := int64(stat.Bavail) * int64(stat.Bsize)
+	used := total - free
+	if used < 0 {
+		used = 0
+	}
+	return total, used
+}
+
+// ReadFirstLine reads and returns the trimmed first line of a file.
+func ReadFirstLine(path string) string {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(content))
+}

internal/apps/edge/observability/linux_test.go

@@ -0,0 +1,78 @@
+package observability
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestParseMemInfoValue(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		line string
+		want int64
+	}{
+		{line: "MemTotal:       16384000 kB", want: 16384000},
+		{line: "MemAvailable:   8192000 kB", want: 8192000},
+		{line: "invalid", want: 0},
+		{line: "MemTotal: not-a-number kB", want: 0},
+	}
+
+	for _, tt := range tests {
+		if got := parseMemInfoValue(tt.line); got != tt.want {
+			t.Fatalf("parseMemInfoValue(%q) = %d, want %d", tt.line, got, tt.want)
+		}
+	}
+}
+
+func TestShouldSkipDiskDevice(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		device string
+		want   bool
+	}{
+		{device: "", want: true},
+		{device: "loop0", want: true},
+		{device: "ram0", want: true},
+		{device: "dm-0", want: true},
+		{device: "sda", want: false},
+		{device: "nvme0n1", want: false},
+	}
+
+	for _, tt := range tests {
+		if got := shouldSkipDiskDevice(tt.device); got != tt.want {
+			t.Fatalf("shouldSkipDiskDevice(%q) = %v, want %v", tt.device, got, tt.want)
+		}
+	}
+}
+
+func TestReadFirstLine(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	path := filepath.Join(dir, "sample.txt")
+	if err := os.WriteFile(path, []byte("  first line\nsecond line\n"), 0o644); err != nil {
+		t.Fatalf("write file: %v", err)
+	}
+
+	if got := ReadFirstLine(path); got != "first line\nsecond line" {
+		t.Fatalf("ReadFirstLine() = %q, want trimmed first line content", got)
+	}
+	if got := ReadFirstLine(filepath.Join(dir, "missing.txt")); got != "" {
+		t.Fatalf("ReadFirstLine(missing) = %q, want empty string", got)
+	}
+}
+
+func TestStatFilesystem(t *testing.T) {
+	t.Parallel()
+
+	total, used := StatFilesystem(t.TempDir())
+	if total <= 0 {
+		t.Fatalf("StatFilesystem() total = %d, want > 0", total)
+	}
+	if used < 0 || used > total {
+		t.Fatalf("StatFilesystem() used = %d, total = %d", used, total)
+	}
+}

internal/apps/edge/runner/wsreconnect.go

@@ -0,0 +1,64 @@
+package runner
+
+import (
+	"context"
+	"log/slog"
+	"time"
+)
+
+type WSConnection interface {
+	Close() error
+}
+
+type WSReconnectConfig struct {
+	ComponentName  string
+	ConnectBackoff time.Duration
+	ReconnectDelay time.Duration
+	OnShutdown     func()
+}
+
+func RunWSReconnectLoop(ctx context.Context, cfg WSReconnectConfig,
+	connect func(context.Context) (WSConnection, error),
+	handle func(context.Context, WSConnection),
+) error {
+	if cfg.ConnectBackoff <= 0 {
+		cfg.ConnectBackoff = 5 * time.Second
+	}
+	if cfg.ReconnectDelay <= 0 {
+		cfg.ReconnectDelay = 2 * time.Second
+	}
+	label := cfg.ComponentName
+	if label == "" {
+		label = "edge"
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			if cfg.OnShutdown != nil {
+				cfg.OnShutdown()
+			}
+			return ctx.Err()
+		default:
+		}
+
+		conn, err := connect(ctx)
+		if err != nil {
+			slog.Error(label+" ws connect failed, will retry", "error", err)
+			SleepContext(ctx, cfg.ConnectBackoff)
+			continue
+		}
+
+		handle(ctx, conn)
+		_ = conn.Close()
+		slog.Info(label + " ws connection closed, reconnecting...")
+		SleepContext(ctx, cfg.ReconnectDelay)
+	}
+}
+
+func SleepContext(ctx context.Context, d time.Duration) {
+	select {
+	case <-ctx.Done():
+	case <-time.After(d):
+	}
+}

internal/apps/edge/updater/restart_unix.go

@@ -0,0 +1,51 @@
+//go:build !windows
+
+package updater
+
+import (
+	"fmt"
+	"log/slog"
+	"os"
+	"syscall"
+)
+
+func replaceAndRestart(execPath string, tmpPath string) error {
+	backupPath := execPath + ".bak"
+	if err := removeBackupBinary(backupPath); err != nil {
+		return err
+	}
+	if err := os.Rename(execPath, backupPath); err != nil {
+		renameErr := err
+		if err := os.Remove(tmpPath); err != nil && !os.IsNotExist(err) {
+			slog.Error("remove tmp binary failed", "path", tmpPath, "error", err)
+			return fmt.Errorf("backup current binary: %w; remove tmp binary: %v", renameErr, err)
+		}
+		return fmt.Errorf("backup current binary: %w", renameErr)
+	}
+	if err := os.Rename(tmpPath, execPath); err != nil {
+		replaceErr := err
+		if err := os.Rename(backupPath, execPath); err != nil {
+			slog.Error("restore backup binary failed", "path", backupPath, "error", err)
+			return fmt.Errorf("replace binary: %w; restore backup binary: %v", replaceErr, err)
+		}
+		return fmt.Errorf("replace binary: %w", replaceErr)
+	}
+	if err := removeBackupBinary(backupPath); err != nil {
+		return err
+	}
+	if err := syscall.Exec(execPath, os.Args, os.Environ()); err != nil {
+		return fmt.Errorf("exec restart: %w", err)
+	}
+	return fmt.Errorf("unreachable after exec")
+}
+
+func removeBackupBinary(path string) error {
+	if err := os.Remove(path); err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		slog.Error("remove backup binary failed", "path", path, "error", err)
+		return err
+	}
+	return nil
+}

internal/apps/edge/updater/restart_unix_test.go

@@ -0,0 +1,15 @@
+//go:build !windows
+
+package updater
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestRemoveBackupBinaryIgnoresMissingFile(t *testing.T) {
+	backupPath := filepath.Join(t.TempDir(), "openflare-agent.bak")
+	if err := removeBackupBinary(backupPath); err != nil {
+		t.Fatalf("expected missing backup cleanup to be ignored: %v", err)
+	}
+}

internal/apps/edge/updater/restart_windows.go

@@ -0,0 +1,53 @@
+//go:build windows
+
+package updater
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func replaceAndRestart(execPath string, tmpPath string) error {
+	backupPath := execPath + ".bak"
+	scriptPath := execPath + ".update.cmd"
+	script := fmt.Sprintf(`@echo off
+setlocal
+:waitloop
+move /Y "%s" "%s" >nul 2>nul
+if errorlevel 1 (
+  ping 127.0.0.1 -n 2 >nul
+  goto waitloop
+)
+move /Y "%s" "%s" >nul 2>nul
+if errorlevel 1 exit /b 1
+start "" %s
+del /Q "%s" >nul 2>nul
+del /Q "%%~f0" >nul 2>nul
+`, execPath, backupPath, tmpPath, execPath, buildWindowsCommandLine(execPath, os.Args[1:]), backupPath)
+	if err := os.WriteFile(scriptPath, []byte(script), 0o700); err != nil {
+		os.Remove(tmpPath)
+		return fmt.Errorf("write restart script: %w", err)
+	}
+	cmd := exec.Command("cmd", "/C", "start", "", scriptPath)
+	if err := cmd.Start(); err != nil {
+		os.Remove(scriptPath)
+		os.Remove(tmpPath)
+		return fmt.Errorf("schedule restart: %w", err)
+	}
+	os.Exit(0)
+	return nil
+}
+
+func buildWindowsCommandLine(execPath string, args []string) string {
+	parts := []string{quoteWindowsArg(execPath)}
+	for _, arg := range args {
+		parts = append(parts, quoteWindowsArg(arg))
+	}
+	return strings.Join(parts, " ")
+}
+
+func quoteWindowsArg(value string) string {
+	return `"` + strings.ReplaceAll(value, `"`, `""`) + `"`
+}

internal/apps/edge/updater/service.go

@@ -0,0 +1,381 @@
+package updater
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"os"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/Rain-kl/Wavelet/pkg/utils"
+)
+
+const maxChecksumAssetSize = 64 * 1024
+
+var replaceAndRestartFunc = replaceAndRestart
+
+type Config struct {
+	LocalVersion string
+	AssetPrefix  string
+	LogLabel     string
+}
+
+type Service struct {
+	httpClient   *http.Client
+	lastCheckKey string
+	localVersion string
+	assetPrefix  string
+	logLabel     string
+}
+
+func New(cfg Config) *Service {
+	return &Service{
+		httpClient:   &http.Client{Timeout: 30 * time.Second},
+		localVersion: cfg.LocalVersion,
+		assetPrefix:  cfg.AssetPrefix,
+		logLabel:     cfg.LogLabel,
+	}
+}
+
+type UpdateOptions struct {
+	Channel string
+	TagName string
+	Force   bool
+}
+
+type githubRelease struct {
+	TagName    string        `json:"tag_name"`
+	Prerelease bool          `json:"prerelease"`
+	Draft      bool          `json:"draft"`
+	Assets     []githubAsset `json:"assets"`
+}
+
+type githubAsset struct {
+	Name               string `json:"name"`
+	BrowserDownloadURL string `json:"browser_download_url"`
+}
+
+func (s *Service) CheckAndUpdate(ctx context.Context, repo string, options UpdateOptions) error {
+	release, err := s.getRelease(ctx, repo, options)
+	if err != nil {
+		return fmt.Errorf("check latest release: %w", err)
+	}
+	if release == nil || release.TagName == "" {
+		return nil
+	}
+
+	remoteVersion := normalizeVersion(release.TagName)
+	localVersion := normalizeVersion(s.localVersion)
+	checkKey := buildReleaseCheckKey(options, remoteVersion)
+
+	if remoteVersion == localVersion {
+		return nil
+	}
+	if !options.Force && checkKey != "" && checkKey == s.lastCheckKey {
+		return nil
+	}
+	if !isNewer(localVersion, remoteVersion) {
+		s.lastCheckKey = checkKey
+		return nil
+	}
+
+	slog.Info(s.logLabel+" update available", "from", localVersion, "to", remoteVersion)
+	assetName := s.assetNameForGOOSGOARCH(runtime.GOOS, runtime.GOARCH)
+	checksumAssetName := assetName + ".sha256"
+
+	var downloadURL string
+	var checksumURL string
+	for _, asset := range release.Assets {
+		switch asset.Name {
+		case assetName:
+			downloadURL = asset.BrowserDownloadURL
+		case checksumAssetName:
+			checksumURL = asset.BrowserDownloadURL
+		}
+	}
+	if downloadURL == "" {
+		s.lastCheckKey = checkKey
+		return fmt.Errorf("no matching asset %q in release %s", assetName, release.TagName)
+	}
+	if checksumURL == "" {
+		return fmt.Errorf("no matching checksum asset %q in release %s", checksumAssetName, release.TagName)
+	}
+
+	expectedChecksum, err := s.downloadChecksum(ctx, checksumURL, assetName)
+	if err != nil {
+		return fmt.Errorf("download checksum: %w", err)
+	}
+
+	execPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("get executable path: %w", err)
+	}
+	if err = s.downloadAndRestart(ctx, downloadURL, expectedChecksum, execPath); err != nil {
+		return fmt.Errorf("download and restart: %w", err)
+	}
+	s.lastCheckKey = checkKey
+	return nil
+}
+
+func (s *Service) getRelease(ctx context.Context, repo string, options UpdateOptions) (*githubRelease, error) {
+	tagName := strings.TrimSpace(options.TagName)
+	if tagName != "" {
+		return s.getReleaseByTag(ctx, repo, tagName)
+	}
+	if strings.EqualFold(strings.TrimSpace(options.Channel), "preview") {
+		return s.getLatestPreviewRelease(ctx, repo)
+	}
+	return s.getLatestStableRelease(ctx, repo)
+}
+
+func (s *Service) getLatestStableRelease(ctx context.Context, repo string) (*githubRelease, error) {
+	url := fmt.Sprintf("https://api.github.com/repos/%s/releases/latest", repo)
+	return s.fetchReleaseFromURL(ctx, url)
+}
+
+func (s *Service) getLatestPreviewRelease(ctx context.Context, repo string) (*githubRelease, error) {
+	url := fmt.Sprintf("https://api.github.com/repos/%s/releases?per_page=20", repo)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("github api returned %s", resp.Status)
+	}
+
+	var releases []githubRelease
+	if err = json.NewDecoder(resp.Body).Decode(&releases); err != nil {
+		return nil, err
+	}
+	for _, release := range releases {
+		if release.Draft || !release.Prerelease {
+			continue
+		}
+		releaseCopy := release
+		return &releaseCopy, nil
+	}
+	return nil, nil
+}
+
+func (s *Service) getReleaseByTag(ctx context.Context, repo string, tag string) (*githubRelease, error) {
+	url := fmt.Sprintf("https://api.github.com/repos/%s/releases/tags/%s", repo, strings.TrimSpace(tag))
+	return s.fetchReleaseFromURL(ctx, url)
+}
+
+func (s *Service) fetchReleaseFromURL(ctx context.Context, url string) (*githubRelease, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			slog.Error("failed to close response body", "error", err)
+		}
+	}(resp.Body)
+
+	if resp.StatusCode == http.StatusNotFound {
+		return nil, nil
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("github api returned %s", resp.Status)
+	}
+
+	return decodeRelease(resp.Body)
+}
+
+func decodeRelease(reader io.Reader) (*githubRelease, error) {
+	var release githubRelease
+	if err := json.NewDecoder(reader).Decode(&release); err != nil {
+		return nil, err
+	}
+	return &release, nil
+}
+
+func (s *Service) downloadChecksum(ctx context.Context, url string, assetName string) (string, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return "", err
+	}
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("checksum download returned %s", resp.Status)
+	}
+
+	content, err := io.ReadAll(io.LimitReader(resp.Body, maxChecksumAssetSize+1))
+	if err != nil {
+		return "", err
+	}
+	if len(content) > maxChecksumAssetSize {
+		return "", fmt.Errorf("checksum asset exceeds %d bytes", maxChecksumAssetSize)
+	}
+	checksum, err := parseSHA256Checksum(string(content), assetName)
+	if err != nil {
+		return "", err
+	}
+	return checksum, nil
+}
+
+func parseSHA256Checksum(content string, assetName string) (string, error) {
+	assetName = strings.TrimSpace(assetName)
+	for _, line := range strings.Split(content, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		if checksum, ok := parseSHA256Line(line, assetName); ok {
+			return checksum, nil
+		}
+	}
+	if assetName == "" {
+		return "", fmt.Errorf("checksum asset does not contain a valid sha256 digest")
+	}
+	return "", fmt.Errorf("checksum asset does not contain a sha256 digest for %q", assetName)
+}
+
+func parseSHA256Line(line string, assetName string) (string, bool) {
+	fields := strings.Fields(line)
+	if len(fields) == 1 && isSHA256Hex(fields[0]) {
+		return strings.ToLower(fields[0]), true
+	}
+	if len(fields) >= 2 && isSHA256Hex(fields[0]) {
+		fileName := strings.TrimPrefix(strings.TrimSpace(fields[1]), "*")
+		if assetName == "" || fileName == assetName {
+			return strings.ToLower(fields[0]), true
+		}
+	}
+
+	prefix := "SHA256("
+	if strings.HasPrefix(line, prefix) {
+		closing := strings.Index(line, ")")
+		if closing > len(prefix) && closing+1 < len(line) {
+			fileName := strings.TrimSpace(line[len(prefix):closing])
+			rest := strings.TrimSpace(line[closing+1:])
+			rest = strings.TrimPrefix(rest, "=")
+			rest = strings.TrimSpace(rest)
+			if isSHA256Hex(rest) && (assetName == "" || fileName == assetName) {
+				return strings.ToLower(rest), true
+			}
+		}
+	}
+	return "", false
+}
+
+func isSHA256Hex(value string) bool {
+	value = strings.TrimSpace(value)
+	if len(value) != sha256.Size*2 {
+		return false
+	}
+	_, err := hex.DecodeString(value)
+	return err == nil
+}
+
+func (s *Service) downloadAndRestart(ctx context.Context, url string, expectedChecksum string, targetPath string) error {
+	expectedChecksum = strings.ToLower(strings.TrimSpace(expectedChecksum))
+	if !isSHA256Hex(expectedChecksum) {
+		return fmt.Errorf("invalid expected sha256 checksum")
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := s.httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download returned %s", resp.Status)
+	}
+
+	tmpPath := targetPath + ".update"
+	if runtime.GOOS == "windows" && !strings.HasSuffix(strings.ToLower(tmpPath), ".exe") {
+		tmpPath += ".exe"
+	}
+	tmpFile, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o600)
+	if err != nil {
+		return err
+	}
+	hasher := sha256.New()
+	if _, err = io.Copy(io.MultiWriter(tmpFile, hasher), resp.Body); err != nil {
+		tmpFile.Close()
+		os.Remove(tmpPath)
+		return err
+	}
+	if err = tmpFile.Close(); err != nil {
+		os.Remove(tmpPath)
+		return err
+	}
+	actualChecksum := hex.EncodeToString(hasher.Sum(nil))
+	if actualChecksum != expectedChecksum {
+		os.Remove(tmpPath)
+		return fmt.Errorf("sha256 checksum mismatch: expected %s, got %s", expectedChecksum, actualChecksum)
+	}
+	if err = os.Chmod(tmpPath, 0o755); err != nil && runtime.GOOS != "windows" {
+		os.Remove(tmpPath)
+		return fmt.Errorf("set executable permission: %w", err)
+	}
+
+	slog.Info(s.logLabel + " binary updated, restarting")
+	return replaceAndRestartFunc(targetPath, tmpPath)
+}
+
+func (s *Service) assetNameForGOOSGOARCH(goos string, goarch string) string {
+	name := fmt.Sprintf("%s-%s-%s", s.assetPrefix, goos, goarch)
+	if goos == "windows" {
+		return name + ".exe"
+	}
+	return name
+}
+
+func normalizeVersion(v string) string {
+	v = strings.TrimSpace(v)
+	v = strings.TrimPrefix(v, "v")
+	return v
+}
+
+func isNewer(local, remote string) bool {
+	return compareVersions(local, remote) < 0
+}
+
+func buildReleaseCheckKey(options UpdateOptions, remoteVersion string) string {
+	channel := strings.TrimSpace(options.Channel)
+	if channel == "" {
+		channel = "stable"
+	}
+	if tagName := strings.TrimSpace(options.TagName); tagName != "" {
+		return channel + ":" + tagName
+	}
+	return channel + ":" + remoteVersion
+}
+
+func compareVersions(local string, remote string) int {
+	return utils.CompareVersions(local, remote)
+}

internal/apps/edge/updater/service_test.go

@@ -0,0 +1,232 @@
+package updater
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+type roundTripFunc func(req *http.Request) (*http.Response, error)
+
+func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req)
+}
+
+func testService(httpClient *http.Client) *Service {
+	return &Service{
+		httpClient:   httpClient,
+		localVersion: "v1.0.0",
+		assetPrefix:  "openflare-agent",
+		logLabel:     "agent",
+	}
+}
+
+func TestGetLatestPreviewRelease(t *testing.T) {
+	service := testService(&http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			if req.URL.String() != "https://api.github.com/repos/Rain-kl/OpenFlare/releases?per_page=20" {
+				t.Fatalf("unexpected request url: %s", req.URL.String())
+			}
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     make(http.Header),
+				Body: io.NopCloser(strings.NewReader(`[
+						{"tag_name":"v1.0.0","prerelease":false},
+						{"tag_name":"v1.1.0-rc.1","prerelease":true}
+					]`)),
+			}, nil
+		}),
+	})
+
+	release, err := service.getRelease(context.Background(), "Rain-kl/OpenFlare", UpdateOptions{Channel: "preview"})
+	if err != nil {
+		t.Fatalf("expected preview release query to succeed: %v", err)
+	}
+	if release == nil || release.TagName != "v1.1.0-rc.1" {
+		t.Fatalf("unexpected preview release: %#v", release)
+	}
+}
+
+func TestGetReleaseByTag(t *testing.T) {
+	service := testService(&http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			if req.URL.String() != "https://api.github.com/repos/Rain-kl/OpenFlare/releases/tags/v1.1.0-rc.1" {
+				t.Fatalf("unexpected request url: %s", req.URL.String())
+			}
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     make(http.Header),
+				Body:       io.NopCloser(strings.NewReader(`{"tag_name":"v1.1.0-rc.1","prerelease":true}`)),
+			}, nil
+		}),
+	})
+
+	release, err := service.getRelease(context.Background(), "Rain-kl/OpenFlare", UpdateOptions{Channel: "preview", TagName: "v1.1.0-rc.1", Force: true})
+	if err != nil {
+		t.Fatalf("expected tag release query to succeed: %v", err)
+	}
+	if release == nil || release.TagName != "v1.1.0-rc.1" {
+		t.Fatalf("unexpected tag release: %#v", release)
+	}
+}
+
+func TestCheckAndUpdateRequiresChecksumAsset(t *testing.T) {
+	assetName := testService(nil).assetNameForGOOSGOARCH(runtime.GOOS, runtime.GOARCH)
+	service := testService(&http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			if req.URL.String() != "https://api.github.com/repos/Rain-kl/OpenFlare/releases/latest" {
+				t.Fatalf("unexpected request url: %s", req.URL.String())
+			}
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     make(http.Header),
+				Body: io.NopCloser(strings.NewReader(`{
+						"tag_name":"v1.0.1",
+						"assets":[
+							{"name":"` + assetName + `","browser_download_url":"https://example.test/agent"}
+						]
+					}`)),
+			}, nil
+		}),
+	})
+
+	err := service.CheckAndUpdate(context.Background(), "Rain-kl/OpenFlare", UpdateOptions{})
+	if err == nil || !strings.Contains(err.Error(), "no matching checksum asset") {
+		t.Fatalf("expected missing checksum asset error, got %v", err)
+	}
+}
+
+func TestParseSHA256Checksum(t *testing.T) {
+	checksum := strings.Repeat("a", sha256.Size*2)
+	testCases := []struct {
+		name    string
+		content string
+		asset   string
+		want    string
+	}{
+		{name: "single digest", content: checksum + "\n", asset: "openflare-agent-linux-amd64", want: checksum},
+		{name: "sha256sum format", content: checksum + "  openflare-agent-linux-amd64\n", asset: "openflare-agent-linux-amd64", want: checksum},
+		{name: "bsd format", content: "SHA256(openflare-agent-linux-amd64)= " + checksum + "\n", asset: "openflare-agent-linux-amd64", want: checksum},
+		{name: "selects matching file", content: strings.Repeat("b", sha256.Size*2) + "  other\n" + checksum + "  openflare-agent-linux-amd64\n", asset: "openflare-agent-linux-amd64", want: checksum},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			got, err := parseSHA256Checksum(testCase.content, testCase.asset)
+			if err != nil {
+				t.Fatalf("expected checksum parse to succeed: %v", err)
+			}
+			if got != testCase.want {
+				t.Fatalf("unexpected checksum: got %s want %s", got, testCase.want)
+			}
+		})
+	}
+}
+
+func TestDownloadAndRestartVerifiesChecksum(t *testing.T) {
+	payload := []byte("new-agent-binary")
+	sum := sha256.Sum256(payload)
+	expectedChecksum := hex.EncodeToString(sum[:])
+	targetPath := filepath.Join(t.TempDir(), "openflare-agent")
+	if err := os.WriteFile(targetPath, []byte("old-agent-binary"), 0o755); err != nil {
+		t.Fatalf("write target: %v", err)
+	}
+
+	var replacedTarget string
+	var replacedTemp string
+	originalReplace := replaceAndRestartFunc
+	replaceAndRestartFunc = func(execPath string, tmpPath string) error {
+		replacedTarget = execPath
+		replacedTemp = tmpPath
+		return nil
+	}
+	t.Cleanup(func() {
+		replaceAndRestartFunc = originalReplace
+	})
+
+	service := testService(&http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     make(http.Header),
+				Body:       io.NopCloser(strings.NewReader(string(payload))),
+			}, nil
+		}),
+	})
+
+	if err := service.downloadAndRestart(context.Background(), "https://example.test/agent", expectedChecksum, targetPath); err != nil {
+		t.Fatalf("expected verified download to succeed: %v", err)
+	}
+	if replacedTarget != targetPath {
+		t.Fatalf("unexpected replace target: %s", replacedTarget)
+	}
+	if replacedTemp == "" {
+		t.Fatal("expected replacement temp path to be recorded")
+	}
+	if _, err := os.Stat(replacedTemp); err != nil {
+		t.Fatalf("expected verified temp binary to remain for replacement: %v", err)
+	}
+}
+
+func TestDownloadAndRestartRejectsChecksumMismatch(t *testing.T) {
+	targetPath := filepath.Join(t.TempDir(), "openflare-agent")
+	if err := os.WriteFile(targetPath, []byte("old-agent-binary"), 0o755); err != nil {
+		t.Fatalf("write target: %v", err)
+	}
+
+	originalReplace := replaceAndRestartFunc
+	replaceAndRestartFunc = func(execPath string, tmpPath string) error {
+		t.Fatal("replace should not run on checksum mismatch")
+		return nil
+	}
+	t.Cleanup(func() {
+		replaceAndRestartFunc = originalReplace
+	})
+
+	service := testService(&http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     make(http.Header),
+				Body:       io.NopCloser(strings.NewReader("tampered")),
+			}, nil
+		}),
+	})
+
+	err := service.downloadAndRestart(context.Background(), "https://example.test/agent", strings.Repeat("0", sha256.Size*2), targetPath)
+	if err == nil || !strings.Contains(err.Error(), "sha256 checksum mismatch") {
+		t.Fatalf("expected checksum mismatch error, got %v", err)
+	}
+	if _, err = os.Stat(targetPath + ".update"); !os.IsNotExist(err) {
+		t.Fatalf("expected temp update file to be removed, stat err=%v", err)
+	}
+}
+
+func TestIsNewerSupportsPrerelease(t *testing.T) {
+	testCases := []struct {
+		name     string
+		local    string
+		remote   string
+		expected bool
+	}{
+		{name: "stable newer than prerelease", local: "1.2.3-rc.1", remote: "1.2.3", expected: true},
+		{name: "same stable not newer", local: "1.2.3", remote: "1.2.3-rc.1", expected: false},
+		{name: "higher prerelease sequence", local: "1.2.3-rc.1", remote: "1.2.3-rc.2", expected: true},
+		{name: "higher minor", local: "1.2.3", remote: "1.3.0-rc.1", expected: true},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			if actual := isNewer(testCase.local, testCase.remote); actual != testCase.expected {
+				t.Fatalf("unexpected compare result: local=%s remote=%s actual=%v expected=%v", testCase.local, testCase.remote, actual, testCase.expected)
+			}
+		})
+	}
+}